Dam-break how in channel transitions is simulated by numerically solvi
ng the system of governing two-dimensional equations. A simple algebra
ic coordinate transformation technique is adopted for converting the g
eneral physical domain of a transition into a rectangular computationa
l domain. The MacCormack scheme is used for solving the transformed eq
uations. Numerical results of the present study show satisfactory agre
ement with the experimental data available in the literature. They als
o match previous numerical results well. Effects of the contractions a
nd expansions on the dam-break flow depth at the dam site is also stud
ied.